Question

Answer 1

`a, <=>` \(\left[{}\begin{matrix}x-3=4\\x-3=-4\end{matrix}\right.\)

`<=>` \(\left[{}\begin{matrix}x=7\\x=-1\end{matrix}\right.\)

`b, <=> x^2 = 100`

`<=>` \(\left[{}\begin{matrix}x=10\\x=-10\end{matrix}\right.\)

`c, <=> 2/9 x = 4/9`

`=> x = 2`

Answer 2

b: =>x-3=4 hoặc x-3=-4

=>x=7 hoặc x=-1

c: =>x²=100

=>x=10 hoặc x=-10

d: =>2/9x=7/9-1/3=4/9

hay x=2

Answer 3

\(b,TH1\left(x-3\right)^2=4^2\\ x-3=4\\ x=7\\ TH2\left(x-3\right)^3=\left(-4\right)^2\\ x-3=-4\\ x=-1\)

c, đk x ≠ 0

\(x^2=100\\ x=10\left(thoanman\right);x=-10\left(thoaman\right)\)

\(d,\dfrac{2}{9}x=\dfrac{7}{9}-\dfrac{1}{3}\\ \dfrac{2}{9}x=\dfrac{7-3}{9}\\ \dfrac{2}{9}x=\dfrac{4}{9}\\ x=2\)

Answer 4

\(b.\Leftrightarrow\left|x-3\right|=4\)

\(\Leftrightarrow\left[{}\begin{matrix}x-3=4\\x-3=-4\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-1\end{matrix}\right.\)

\(c.\Leftrightarrow x^2=100\left(x\ne0\right)\)

\(\Leftrightarrow\left|x\right|=10\)
\(\Leftrightarrow\left[{}\begin{matrix}x=10\left(tm\right)\\x=-10\left(tm\right)\end{matrix}\right.\)

\(d.\Leftrightarrow\dfrac{3}{9}+\dfrac{2x}{9}=\dfrac{7}{9}\)

\(\Leftrightarrow3+2x=7\)

\(\Leftrightarrow x=2\)

Answer 5

`a, <=>` \(\left[{}\begin{matrix}x-3=4\\x-3=-4\end{matrix}\right.\)

`<=>` \(\left[{}\begin{matrix}x=7\\x=-1\end{matrix}\right.\)

`b, <=> x^2 = 100 ( x ne 0).`

`<=>` \(\left[{}\begin{matrix}x=10\\x=-10\end{matrix}\right.\)

`c, <=> 2/9 x = 4/9`

`=> x = 2`